Facile synthesis of rhombohedral type FeF 3 introduced via two consecutive steps is introduced: i) acidic treatment of Fe 2 O 3 followed by thermal evaporation at 80 °C resulting in hydrated β-FeF 3 ·3H 2 O and ii) a simple thermal decomposition of the as-received β-FeF 3 ·3H 2 O at 400 °C under an Ar atmosphere. A Rietveld refinement of x-ray diffraction data for the as-synthesized FeF 3 indicates the formation of a highly crystalline FeF 3 structure with a R3¯c space group. To overcome the high ionicity and improve the diffusivity, FeF 3 is ball-milled with the aid of carbon (acetylene black). The electrochemical performance of nanosized FeF 3 is not favored in voltage range of 1.5–4.5 V because the repetitive intercalation–conversion reaction accelerates the structural disruption within a few cycles, although a high capacity (518 mAh (g-fluoride) −1 at 20 mA g −1 ) is observed, assisted by the three-electron redox of Fe 3+/0 . Raising the lower cut-off voltage to 2 V, which allows only intercalation reaction, the FeF 3 delivers a high capacity of 224 mAh g −1 with significantly improved capacity retention (71% at 100th cycle).